Based on the data of buoy, island and inland stations of the Beibu Gulf from 2016 to 2017, the seasonal variation, occurrence and disappearance characteristics, and duration of fogs and the difference between sea and land heavy fogs are statistically analyzed. The result shows that the number of sea fog days occurred in 2016 is 37 and 19 in 2017. The largest number of sea fog days occurred in March; the second is in April; and there was no sea fog occurred in December and from June to October every year. The peak time of sea fog appearing was 03:00 to 05:00, and the peak time of dissipation was 08:00 to 10:00. The duration of sea fog maintenance was within 3 hours. The generation time of sea fogs was different in different areas and underlying surfaces over the Beibu Gulf. The generation time of sea fogs (buoy stations) was about 3 hours earlier than those of island fogs (Weizhou Station) and coastal fogs (Beihai Station), and the dissipation time was about 3 hours later. The sea fogs over the Beibu Gulf mostly took place under the condition when wind speed was less than 5 m/s (l to 3 m/s is most suitable) and wind direction was NNE to SE; ninetyfive percent of sea fogs occurred when the sea water temperature was lower than 25.0 ℃.